Mounting tubeless tires on wheel rims by automobile manufacturers is normally accomplished by high production devices where a wheel is placed on a conveyor, the tire is preliminary positioned relative to the rim, and the rim and tire are conveyed from station to station. At the various stations, the tire can be soaped, forced over the rim, and mounted intermediate the upper and lower lips of the rim. Optionally, the rim and tire may be rotated relative to each other in accordance with previously applied reference points. The tire is inflated to a predetermined pressure at an inflation work station.
To reduce the duration of time required for inflation, it is known to impose an annular axial force on one of the tire side walls which causes the other tire side wall to seal against a support surface while the deflected side wall bead is displaced from the lip of the rim. An inflation chamber is defined by the support surface and the tire, and compressed air is forced into the tire around the displaced side wall bead. After the desired pressure is achieved in the inflation chamber, the deflected tire side wall is permitted to expand to seat the bead against the corresponding lip of the rim to maintain the inflation pressure. This process permits inflation of the tire to be accomplished in a very short period of time.
An inflation chamber for a high production tire inflation devices includes the interior of the tire, where pressurization of the chamber produces the desired pressure within the tire. To define the inflation chamber, an annular tire side wall seal is normally employed to engage the tire side wall and to displace the bead associated with the side wall from the lip of the rim. Sufficient pressure is applied to seal the opposite tire side wall against the support surface. Pressurizing the chamber drives the bead associated with the opposite tire side wall into engagement with the lip of the rim while the deflected tire side wall maintains an open passage until the pressurization of the inflation chamber is complete. The deflected tire side wall is then permitted to expand to seat the associated bead against the lip of the rim to maintain the inflation pressure.
Alternatively, an annular inflation chamber can be defined to include the interior of the tire, an annular wheel seal employed to engage the rim, and an annular tire side wall seal employed to engage the tire side wall for displacing the side wall with respect to the lip of the rim. In this configuration, no support surface or sealing device is associated with the opposite side of the tire as a seal, since the seal opposite from the displaced side wall is achieved by the engagement of the tire bead with the lip of the rim during the inflation process. Typically, the side wall engaging seal and the wheel rim engaging device are displace able with respect to each other to produce the desired sequence of operation for this type of annular inflation chamber.
Known tire inflation devices typically can handle only a limited variation in tire sizes due to the predetermined diameter of the annular tire side wall seal used to define the inflation chamber and deflect the tire side wall during the inflation process. Most tire inflation devices require the size of the sealing structure for the rim and/or tire side wall to be changed when different sizes of wheel rims and tires are to be inflated. Changeover of the inflation line from one tire size to another is time consuming and expensive. Furthermore, there is often a need to mix tire sizes on an inflation line as required for production purposes.